From: Anton Altaparmakov Date: Mon, 7 Mar 2005 21:43:38 +0000 (+0000) Subject: NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after X-Git-Tag: v2.6.13-rc4~89^2~33 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c0c1cc0e46b36347f11b566f99087dc5e6fc1b89;p=linux-2.6 NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after dropping the read lock and taking the write lock we were not checking whether someone else did not already do the work we wanted to do. - Rename ntfs_find_vcn_nolock() to ntfs_attr_find_vcn_nolock(). - Tidy up some comments in fs/ntfs/runlist.c. - Add LCN_ENOMEM and LCN_EIO definitions to fs/ntfs/runlist.h. Signed-off-by: Anton Altaparmakov --- diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index 4af6ae6ff1..7507a56a49 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -92,6 +92,11 @@ ToDo/Notes: non-resident in fs/ntfs/attrib.c::ntfs_attr_can_be_non_resident(). - Add fs/ntfs/attrib.c::ntfs_attr_vcn_to_lcn_nolock() used by the new write code. + - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after + dropping the read lock and taking the write lock we were not checking + whether someone else did not already do the work we wanted to do. + - Rename fs/ntfs/attrib.c::ntfs_find_vcn_nolock() to + ntfs_attr_find_vcn_nolock() and update all callers. 2.1.22 - Many bug and race fixes and error handling improvements. diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 1610f1cd28..6de5e04e97 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -193,19 +193,19 @@ retry_remap: } /** - * ntfs_find_vcn_nolock - find a vcn in the runlist described by an ntfs inode + * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode * @ni: ntfs inode describing the runlist to search * @vcn: vcn to find * @write_locked: true if the runlist is locked for writing * * Find the virtual cluster number @vcn in the runlist described by the ntfs * inode @ni and return the address of the runlist element containing the @vcn. - * The runlist is left locked and the caller has to unlock it. In the error - * case, the runlist is left in the same locking state as on entry. * - * Note if @write_locked is FALSE the lock may be dropped inside the function - * so you cannot rely on the runlist still being the same when this function - * returns. + * If the @vcn is not mapped yet, the attempt is made to map the attribute + * extent containing the @vcn and the vcn to lcn conversion is retried. + * + * If @write_locked is true the caller has locked the runlist for writing and + * if false for reading. * * Note you need to distinguish between the lcn of the returned runlist element * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on @@ -221,13 +221,12 @@ retry_remap: * -ENOMEM - Not enough memory to map runlist. * -EIO - Critical error (runlist/file is corrupt, i/o error, etc). * - * Locking: - The runlist must be unlocked on entry. - * - On failing return, the runlist is unlocked. - * - On successful return, the runlist is locked. If @need_write us - * true, it is locked for writing. Otherwise is is locked for - * reading. + * Locking: - The runlist must be locked on entry and is left locked on return. + * - If @write_locked is FALSE, i.e. the runlist is locked for reading, + * the lock may be dropped inside the function so you cannot rely on + * the runlist still being the same when this function returns. */ -runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, +runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, const BOOL write_locked) { runlist_element *rl; @@ -268,6 +267,12 @@ retry_remap: if (!write_locked) { up_read(&ni->runlist.lock); down_write(&ni->runlist.lock); + if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) != + LCN_RL_NOT_MAPPED)) { + up_write(&ni->runlist.lock); + down_read(&ni->runlist.lock); + goto retry_remap; + } } err = ntfs_map_runlist_nolock(ni, vcn); if (!write_locked) { diff --git a/fs/ntfs/attrib.h b/fs/ntfs/attrib.h index 75041c89c7..e0a50f1ca7 100644 --- a/fs/ntfs/attrib.h +++ b/fs/ntfs/attrib.h @@ -66,8 +66,8 @@ extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn); extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, const BOOL write_locked); -extern runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, - const BOOL write_locked); +extern runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, + const VCN vcn, const BOOL write_locked); int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name, const u32 name_len, const IGNORE_CASE_BOOL ic, diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c index f2b7f8582c..6e584ab743 100644 --- a/fs/ntfs/lcnalloc.c +++ b/fs/ntfs/lcnalloc.c @@ -850,7 +850,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count, /* This returns with ni->runlist locked for reading on success. */ down_read(&ni->runlist.lock); - rl = ntfs_find_vcn_nolock(ni, start_vcn, FALSE); + rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, FALSE); if (IS_ERR(rl)) { if (!is_rollback) ntfs_error(vol->sb, "Failed to find first runlist " @@ -904,7 +904,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count, /* Attempt to map runlist. */ vcn = rl->vcn; - rl = ntfs_find_vcn_nolock(ni, vcn, FALSE); + rl = ntfs_attr_find_vcn_nolock(ni, vcn, FALSE); if (IS_ERR(rl)) { err = PTR_ERR(rl); if (!is_rollback) diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c index 66ef6e275a..61ce09f1b6 100644 --- a/fs/ntfs/mft.c +++ b/fs/ntfs/mft.c @@ -1297,7 +1297,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol) read_lock_irqsave(&mftbmp_ni->size_lock, flags); ll = mftbmp_ni->allocated_size; read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); - rl = ntfs_find_vcn_nolock(mftbmp_ni, + rl = ntfs_attr_find_vcn_nolock(mftbmp_ni, (ll - 1) >> vol->cluster_size_bits, TRUE); if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { up_write(&mftbmp_ni->runlist.lock); @@ -1727,8 +1727,8 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) read_lock_irqsave(&mft_ni->size_lock, flags); ll = mft_ni->allocated_size; read_unlock_irqrestore(&mft_ni->size_lock, flags); - rl = ntfs_find_vcn_nolock(mft_ni, (ll - 1) >> vol->cluster_size_bits, - TRUE); + rl = ntfs_attr_find_vcn_nolock(mft_ni, + (ll - 1) >> vol->cluster_size_bits, TRUE); if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { up_write(&mft_ni->runlist.lock); ntfs_error(vol->sb, "Failed to determine last allocated " diff --git a/fs/ntfs/runlist.c b/fs/ntfs/runlist.c index 1b344dd4d4..3f479f1766 100644 --- a/fs/ntfs/runlist.c +++ b/fs/ntfs/runlist.c @@ -933,17 +933,18 @@ err_out: * * It is up to the caller to serialize access to the runlist @rl. * - * Since lcns must be >= 0, we use negative return values with special meaning: + * Since lcns must be >= 0, we use negative return codes with special meaning: * - * Return value Meaning / Description + * Return code Meaning / Description * ================================================== - * -1 = LCN_HOLE Hole / not allocated on disk. - * -2 = LCN_RL_NOT_MAPPED This is part of the runlist which has not been - * inserted into the runlist yet. - * -3 = LCN_ENOENT There is no such vcn in the attribute. + * LCN_HOLE Hole / not allocated on disk. + * LCN_RL_NOT_MAPPED This is part of the runlist which has not been + * inserted into the runlist yet. + * LCN_ENOENT There is no such vcn in the attribute. * * Locking: - The caller must have locked the runlist (for reading or writing). - * - This function does not touch the lock. + * - This function does not touch the lock, nor does it modify the + * runlist. */ LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn) { diff --git a/fs/ntfs/runlist.h b/fs/ntfs/runlist.h index 7107fde59d..60c42f3a3f 100644 --- a/fs/ntfs/runlist.h +++ b/fs/ntfs/runlist.h @@ -66,6 +66,8 @@ typedef enum { LCN_HOLE = -1, /* Keep this as highest value or die! */ LCN_RL_NOT_MAPPED = -2, LCN_ENOENT = -3, + LCN_ENOMEM = -4, + LCN_EIO = -5, } LCN_SPECIAL_VALUES; extern runlist_element *ntfs_runlists_merge(runlist_element *drl,