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2011-03-18Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6Linus Torvalds
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (25 commits) UBIFS: clean-up commentaries UBIFS: save 128KiB or more RAM UBIFS: allocate orphans scan buffer on demand UBIFS: allocate lpt dump buffer on demand UBIFS: allocate ltab checking buffer on demand UBIFS: allocate scanning buffer on demand UBIFS: allocate dump buffer on demand UBIFS: do not check data crc by default UBIFS: simplify UBIFS Kconfig menu UBIFS: print max. index node size UBIFS: handle allocation failures in UBIFS write path UBIFS: use max_write_size during recovery UBIFS: use max_write_size for write-buffers UBIFS: introduce write-buffer size field UBI: incorporate LEB offset information UBIFS: incorporate maximum write size UBI: provide LEB offset information UBI: incorporate maximum write size UBIFS: fix LEB number in printk UBIFS: restrict world-writable debugfs files ...
2011-03-16UBIFS: clean-up commentariesArtem Bityutskiy
Clean-up commentaries in debug.h and remove references to non-existing symblols. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: save 128KiB or more RAMArtem Bityutskiy
When debugging is enabled, we allocate a buffer of PEB size for various debugging purposes. However, now all users of this buffer are gone and we can safely remove it and save 128KiB or more RAM. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: allocate orphans scan buffer on demandArtem Bityutskiy
Instead of using pre-allocated 'c->dbg->buf' buffer in 'dbg_scan_orphans()', dynamically allocate it when needed. The intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and save 128KiB of RAM (or more if PEB size is larger). Indeed, currently we allocate this memory even if the user never enables any self-check, which is wasteful. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: allocate lpt dump buffer on demandArtem Bityutskiy
Instead of using pre-allocated 'c->dbg->buf' buffer in 'dump_lpt_leb()', dynamically allocate it when needed. The intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and save 128KiB of RAM (or more if PEB size is larger). Indeed, currently we allocate this memory even if the user never enables any self-check, which is wasteful. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: allocate ltab checking buffer on demandArtem Bityutskiy
Instead of using pre-allocated 'c->dbg->buf' buffer in 'dbg_check_ltab_lnum()', dynamically allocate it when needed. The intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and save 128KiB of RAM (or more if PEB size is larger). Indeed, currently we allocate this memory even if the user never enables any self-check, which is wasteful. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: allocate scanning buffer on demandArtem Bityutskiy
Instead of using pre-allocated 'c->dbg->buf' buffer in 'scan_check_cb()', dynamically allocate it when needed. The intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and save 128KiB of RAM (or more if PEB size is larger). Indeed, currently we allocate this memory even if the user never enables any self-check, which is wasteful. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16UBIFS: allocate dump buffer on demandArtem Bityutskiy
Instead of using pre-allocated 'c->dbg->buf' buffer in 'dbg_dump_leb()', dynamically allocate it when needed. The intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and save 128KiB of RAM (or more if PEB size is larger). Indeed, currently we allocate this memory even if the user never enables any self-check, which is wasteful. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-15fs: Remove i_nlink check from file system link callbackAneesh Kumar K.V
Now that VFS check for inode->i_nlink == 0 and returns proper error, remove similar check from file system Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-11UBIFS: do not check data crc by defaultArtem Bityutskiy
Change the default UBIFS behavior WRT data CRC checking. Currently, UBIFS checks data CRC when reading, which slows it down quite a bit, and this is the default option. However, it looks like in average user does not need this feature and would prefer faster read speed over extra reliability. And this seems to be de-facto standard that file-systems do not check data CRC every time they read from the media. Thus, make UBIFS default behavior so that it does not check data CRC. This corresponds to the no_chk_data_crc mount option. Those users who need extra protection can always enable it using the chk_data_crc option. Please, read more information about this feature here: http://www.linux-mtd.infradead.org/doc/ubifs.html#L_checksumming Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-11UBIFS: simplify UBIFS Kconfig menuArtem Bityutskiy
Remove debug message level and debug checks Kconfig options as they proved to be useless anyway. We have sysfs interface which we can use for fine-grained debugging messages and checks selection, see Documentation/filesystems/ubifs.txt for mode details. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-11UBIFS: print max. index node sizeArtem Bityutskiy
Improve debugging messages by printing the maximum index node size on mount. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-11UBIFS: handle allocation failures in UBIFS write pathMatthew L. Creech
Running kernel 2.6.37, my PPC-based device occasionally gets an order-2 allocation failure in UBIFS, which causes the root FS to become unwritable: kswapd0: page allocation failure. order:2, mode:0x4050 Call Trace: [c787dc30] [c00085b8] show_stack+0x7c/0x194 (unreliable) [c787dc70] [c0061aec] __alloc_pages_nodemask+0x4f0/0x57c [c787dd00] [c0061b98] __get_free_pages+0x20/0x50 [c787dd10] [c00e4f88] ubifs_jnl_write_data+0x54/0x200 [c787dd50] [c00e82d4] do_writepage+0x94/0x198 [c787dd90] [c00675e4] shrink_page_list+0x40c/0x77c [c787de40] [c0067de0] shrink_inactive_list+0x1e0/0x370 [c787de90] [c0068224] shrink_zone+0x2b4/0x2b8 [c787df00] [c0068854] kswapd+0x408/0x5d4 [c787dfb0] [c0037bcc] kthread+0x80/0x84 [c787dff0] [c000ef44] kernel_thread+0x4c/0x68 Similar problems were encountered last April by Tomasz Stanislawski: http://patchwork.ozlabs.org/patch/50965/ This patch implements Artem's suggested fix: fall back to a mutex-protected static buffer, allocated at mount time. I tested it by forcing execution down the failure path, and didn't see any ill effects. Artem: massaged the patch a little, improved it so that we'd not allocate the write reserve buffer when we are in R/O mode. Signed-off-by: Matthew L. Creech <mlcreech@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-08UBIFS: use max_write_size during recoveryArtem Bityutskiy
When recovering from unclean reboots UBIFS scans the journal and checks nodes. If a corrupted node is found, UBIFS tries to check if this is the last node in the LEB or not. This is is done by checking if there only 0xFF bytes starting from the next min. I/O unit. However, since now we write in c->max_write_size, we should actually check for 0xFFs starting from the next max. write unit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-08UBIFS: use max_write_size for write-buffersArtem Bityutskiy
Switch write-buffers from 'c->min_io_size' to 'c->max_write_size' which presumably has to be more write speed-efficient. However, when write-buffer is synchronized, write only the the min. I/O units which contain the data, do not write whole write-buffer. This is more space-efficient. Additionally, this patch takes into account that the LEB might not start from the max. write unit-aligned address. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-08UBIFS: introduce write-buffer size fieldArtem Bityutskiy
Currently we assume write-buffer size is always min_io_size. But this is about to change and write-buffers may be of variable size. Namely, they will be of max_write_size at the beginning, but will get smaller when we are approaching the end of LEB. This is a preparation patch which introduces 'size' field in the write-buffer structure which carries the current write-buffer size. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-08UBI: incorporate LEB offset informationArtem Bityutskiy
Incorporate the LEB offset information into UBIFS. We'll use this information in one of the next patches to figure out what are the max. write size offsets relative to the PEB. So this patch is just a preparation. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-08UBIFS: incorporate maximum write sizeArtem Bityutskiy
Incorporate maximum write size into the UBIFS description data structure. This patch just introduces new 'c->max_write_size' and 'c->max_write_shift' fields as a preparation for the following patches. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-08UBIFS: fix LEB number in printkArtem Bityutskiy
This is a minor patch which fixes the LEB number we print when corrupted empty space is found. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06UBIFS: restrict world-writable debugfs filesVasiliy Kulikov
Don't allow everybody to dump sensitive information about filesystems. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06UBIFS: describe UBIFS recovery logic some moreArtem Bityutskiy
This patch adds more commentaries about UBIFS recovery logic which should explain the famous UBIFS "corrupt empty space" errors. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06UBIFS: remove double semicolonArtem Bityutskiy
Just a tiny clean-up - remove ;; Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-25UBIFS: do not start the commit if there is nothing to commitArtem Bityutskiy
This patch fixes suboptimal UBIFS 'sync_fs()' implementation which causes flash I/O even if the file-system is synchronized. E.g., a 'printk()' in the MTD erasure function (e.g., 'nand_erase_nand()') can show that for every 'sync' shell command UBIFS erases at least one eraseblock. So '$ while true; do sync; done' will cause huge amount of flash I/O. The reason for this is that UBIFS commits in 'sync_fs()', and starts the commit even if there is nothing to commit, e.g., it anyway changes the log. This patch adds a check in the 'do_commit()' UBIFS functions which prevents the commit if there is nothing to commit. Reported-by: Hans J. Koch <hjk@linutronix.de> Tested-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-17UBIFS: introduce mounting flagArtem Bityutskiy
This is a preparational patch which removes the 'c->always_chk_crc' which was set during mounting and remounting to R/W mode and introduces 'c->mounting' flag which is set when mounting. Now the 'c->always_chk_crc' flag is the same as 'c->remounting_rw && c->mounting'. This patch is a preparation for the next one which will need to know when we are mounting and remounting to R/W mode, which is exactly what 'c->always_chk_crc' effectively is, but its name does not suite the next patch. The other possibility would be to just re-name it, but then we'd end up with less logical flags coverage. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-17UBIFS: re-arrange variables in ubifs_infoArtem Bityutskiy
This is a cosmetic patch which re-arranges variables in 'struct ubifs_info' so that all boolean-like variables which are only changed during mounting or re-mounting to R/W mode are places together. Then they are turned into bit-fields, which makes the structure a little bit smaller. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-10-29convert ubifsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26new helper: ihold()Al Viro
Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-22Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6Linus Torvalds
* 'linux-next' of git://git.infradead.org/ubifs-2.6: UBIFS: do not allocate unneeded scan buffer UBIFS: do not forget to cancel timers UBIFS: remove a bit of unneeded code UBIFS: add a commentary about log recovery UBIFS: avoid kernel error if ubifs superblock read fails UBIFS: introduce new flags for RO mounts UBIFS: introduce new flag for RO due to errors UBIFS: check return code of pnode_lookup UBIFS: check return code of ubifs_lpt_lookup UBIFS: improve error reporting when reading bad node UBIFS: introduce list sorting debugging checks UBIFS: fix assertion warnings in comparison function UBIFS: mark unused key objects as invalid UBIFS: do not write rubbish into truncation scanning node UBIFS: improve assertion in node comparison functions UBIFS: do not use key type in list_sort UBIFS: do not look up truncation nodes UBIFS: fix assertion warning UBIFS: do not treat ENOSPC specially UBIFS: switch to RO mode after synchronizing
2010-10-21UBIFS: do not allocate unneeded scan bufferArtem Bityutskiy
In 'ubifs_replay_journal()' we allocate 'sbuf' for scanning the log. However, we already have 'c->sbuf' for these purposes, so do not allocate yet another one. This reduces UBIFS memory consumption while recovering. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-21UBIFS: do not forget to cancel timersArtem Bityutskiy
This is a bug-fix: when we unmount, and we are currently in R/O mode because of an error - we do not sync write-buffers, which means we also do not cancel write-buffer timers we may possibly have armed. This patch fixes the issue. The issue can easily be reproduced by enabling UBIFS failure debug mode (echo 4 > /sys/module/ubifs/parameters/debug_tsts) and unmounting as soon as a failure happen. At some point the system oopses because we have an armed hrtimer but UBIFS is unmounted already. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-21UBIFS: remove a bit of unneeded codeArtem Bityutskiy
This is a clean-up patch which: 1. Removes explicite 'hrtimer_cancel()' after 'ubifs_wbuf_sync()' in 'ubifs_remount_ro()', because the timers will be canceled by 'ubifs_wbuf_sync()', no need to cancel them for the second time. 2. Remove "if (c->jheads)" check from 'ubifs_put_super()', because at journal heads must always be allocated there, since we checked earlier that we were mounted R/W, and the olny situation when journal heads are not allocated is when mounter or re-mounted R/O. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-17UBIFS: add a commentary about log recoveryArtem Bityutskiy
Add a commentary which elaborates that 'ubifs_recover_log_leb()' recovers only the last log LEB, not any. Also remove some unneeded newlines. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-09-28UBIFS: avoid kernel error if ubifs superblock read failsSteffen Sledz
.get_sb is called on mounts with automatic fs detection too, so this function should print an error if it cannot read the superblock in debug mode only (new behaviour conforms the other fs types) Signed-off-by: Steffen Sledz <sledz@dresearch.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-09-19UBIFS: introduce new flags for RO mountsArtem Bityutskiy
Commit 2fde99cb55fb9d9b88180512a5e8a5d939d27fec "UBIFS: mark VFS SB RO too" introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the VFS superblock when it switches to R/O mode due to an error. This was done to make VFS show the R/O UBIFS flag in /proc/mounts. However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this flag can only change when we re-mount. For example, 'ubifs_put_super()'. This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O). This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'. This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to 'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write anything if the FS was mounter R/O. All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed and now we test the 'c->ro_mount' flag instead, because it preserves the original UBIFS mount type, unlike the 'MS_RDONLY' flag. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-09-17UBIFS: introduce new flag for RO due to errorsArtem Bityutskiy
The R/O state may have various reasons: 1. The UBI volume is R/O 2. The FS is mounted R/O 3. The FS switched to R/O mode because of an error However, in UBIFS we have only one variable which represents cases 1 and 3 - 'c->ro_media'. Indeed, we set this to 1 if we switch to R/O mode due to an error, and then we test it in many places to make sure that we stop writing as soon as the error happens. But this is very unclean. One consequence of this, for example, is that in 'ubifs_remount_fs()' we use 'c->ro_media' to check whether we are in R/O mode because on an error, and we print a message in this case. However, if we are in R/O mode because the media is R/O, our message is bogus. This patch introduces new flag - 'c->ro_error' which is set when we switch to R/O mode because of an error. It also changes all "if (c->ro_media)" checks to "if (c->ro_error)" checks, because this is what the checks actually mean. We do not need to check for 'c->ro_media' because if the UBI volume is in R/O mode, we do not allow R/W mounting, and now writes can happen. This is guaranteed by VFS. But it is good to double-check this, so this patch also adds many "ubifs_assert(!c->ro_media)" checks. In the 'ubifs_remount_fs()' function this patch makes a bit more changes - it fixes the error messages as well. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-09-07UBIFS: check return code of pnode_lookupVasiliy Kulikov
Function pnode_lookup may return ERR_PTR(...). Check for it. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-09-07UBIFS: check return code of ubifs_lpt_lookupVasiliy Kulikov
Function ubifs_lpt_lookup may return ERR_PTR(...). Check for it. [Tweaked by Artem Bityutskiy] Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: improve error reporting when reading bad nodeArtem Bityutskiy
When an error happens during validation of read node, the typical situation is that the LEB we read is unmapped (due to some bug). It is handy to include the mapping status into the error message. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: introduce list sorting debugging checksArtem Bityutskiy
The UBIFS bug in the GC list sorting comparison functions inspired me to write internal debugging check functions which verify that the list of nodes is sorted properly. So, this patch implements 2 new debugging functions: o 'dbg_check_data_nodes_order()' - check order of data nodes list o 'dbg_check_nondata_nodes_order()' - check order of non-data nodes list The debugging functions are executed only if general UBIFS debugging checks are enabled. And they are compiled out if UBIFS debugging is disabled. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: fix assertion warnings in comparison functionArtem Bityutskiy
When running the integrity test ('integck' from mtd-utils) on current UBIFS on 2.6.35, I see that assertions in UBIFS 'list_sort()' comparison functions trigger sometimes, e.g.: UBIFS assert failed in data_nodes_cmp at 132 (pid 28311) My investigation showed that this happens when 'list_sort()' calls the 'cmp()' function with equivalent arguments. In this case, the 'struct list_head' parameter, passed to 'cmp()' is bogus, and it does not belong to any element in the original list. And this issue seems to be introduced by commit: commit 835cc0c8477fdbc59e0217891d6f11061b1ac4e2 Author: Don Mullis <don.mullis@gmail.com> Date: Fri Mar 5 13:43:15 2010 -0800 It is easy to work around the issue by doing: if (a == b) return 0; in UBIFS. It works, but 'lib_sort()' should nevertheless be fixed. Although it is harmless to have this piece of code in UBIFS. This patch adds that code to both UBIFS 'cmp()' functions: 'data_nodes_cmp()' and 'nondata_nodes_cmp()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: mark unused key objects as invalidArtem Bityutskiy
When scanning the flash, UBIFS builds a list of flash nodes of type 'struct ubifs_scan_node'. Each scanned node has a 'snod->key' field. This field is valid for most of the nodes, but invalid for some node type, e.g., truncation nodes. It is safer to explicitly initialize such keys to something invalid, rather than leaving them initialized to all zeros, which has key type of UBIFS_INO_KEY. This patch introduces new "fake" key type UBIFS_INVALID_KEY and initializes unused 'snod->key' objects to this type. It also adds debugging assertions in the TNC code to make sure no one ever tries to look these nodes up in the TNC. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: do not write rubbish into truncation scanning nodeArtem Bityutskiy
In the scanning code, in 'ubifs_add_snod()', we write rubbish into 'snod->key', because we assume that on-flash truncation nodes have a key, but they do not. If the other parts of UBIFS then mistakenly try to look-up the truncation node key (they should not do this, but may do because of a bug), we can succeed and corrupt TNC. It looks like we did have such a situation in 'sort_nodes()' in gc.c. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: improve assertion in node comparison functionsArtem Bityutskiy
Improve assertions in gc.c in the comparison functions for 'list_sort()': check key types _and_ node types. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: do not use key type in list_sortArtem Bityutskiy
In comparison function for 'list_sort()' we use key type to distinguish between node types. However, we have a bit simper way to detect node type - 'snod->type'. This more logical to use, comparing to decoding key types. Also allows to get rid of 2 local variables. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: do not look up truncation nodesArtem Bityutskiy
When moving nodes in GC, do not try to look up truncation nodes in TNC, because they do not exist there. This would be harmless, because the TNC look-up would fail, if we did not have bug 'ubifs_add_snod()' which reads garbage into 'snod->key'. But in any case, it is less error prone to explicitly ignore everything but inode, data, dentry and xentry nodes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: fix assertion warningArtem Bityutskiy
This patch fixes the following false assertion warning: UBIFS assert failed in data_nodes_cmp at 130 (pid 15107) The assertion was wrong because it did not take into account that the node can be an xentry. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: do not treat ENOSPC speciallyArtem Bityutskiy
'ubifs_garbage_collect_leb()' should never return '-ENOSPC', and if it does, this is an error. Thus, do not treat this error code specially. '-EAGAIN' is a special error code, but not '-ENOSPC'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-08-30UBIFS: switch to RO mode after synchronizingArtem Bityutskiy
In 'ubifs_garbage_collect()' on error path, we first switch to R/O mode, and then synchronize write-buffers (to make sure no data are lost). But the GC write-buffer synchronization will fail, because we are already in R/O mode. This patch re-orders this and makes sure we first synchronize the write-buffer, and then switch to R/O mode. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>